1. Field of the Invention
Priority is claimed on Japanese Patent Application No. 2004-361140, filed Dec. 14, 2004, the contents of which are incorporated herein by reference.
The present invention relates to a paper leaf detecting device that detects leaves of paper.
2. Description of Related Art
In order to prevent counterfeiting or in order to identify a banknote type or the like, security threads are provided in various leaves of paper such as banknotes and the like. Namely, by providing a security thread having, for example, predetermined magnetic properties in leaves of paper, the genuineness and the like of the leaves of paper can be identified depending on whether or not this security thread is detected and the type of money can be identified from the magnetic properties.
Information that has been encoded using magnetic intensity or the like is provided by being arrayed in the lengthwise direction of these security threads. If information is provided in a security thread that is arrayed in the lengthwise direction of the security thread, then it is necessary for the detecting side to detect by scanning the security thread in the lengthwise direction thereof. If the security thread is aligned in the transporting direction of leaves of paper, then if a magnetic sensor is provided at a position traveled over by the security thread, it is possible using this magnetic sensor device to perform a scan using the transporting of the leaves of paper or the like. However, if the security thread is perpendicular relative to the transporting direction of the leaves of paper, then in this type of magnetic sensor device it is not possible to scan using the transporting of the leaves of paper. Because of this, a technology (see Japanese Patent Application Unexamined Publication No. 9-24686) exists that, by placing a linear magnetic sensor device obliquely relative to the transporting direction of the leaves of paper, makes it possible to scan using the transporting of the leaves of paper even when the security thread is perpendicular to the transporting direction of the leaves of paper.
However, as is described above, in an apparatus in which a linear magnetic sensor device is placed obliquely relative to the transporting direction of the leaves of paper, the space used to position the magnetic sensor device is enlarged particularly in the transporting direction of the leaves of paper. As a result, the problem arises that the size of the device becomes enlarged in this direction. This type of problem also arises unrelated to any detection of the above described security thread when information is detected by performing scanning in a direction that is perpendicular to the transporting direction of the leaves of paper at the same time as the leaves of paper are being transported.
Accordingly, it is an object of the present invention to provide a paper leaf detecting device that makes it possible to detect information by performing scanning in a direction that is perpendicular to the transporting direction of the paper leaves at the same time as the leaves of paper are being transported, and that also prevents size enlargement in the transporting direction of the leaves of paper.